Length conservative surgical instrument

ABSTRACT

A surgical instrument is described that includes a surgical effector moving with N degrees of freedom for manipulation of objects at a surgical site during surgical procedures. The N degrees of freedom are manipulated by N+1 input controllers and a plurality of cables, the controllers and cables coupled to the surgical effector and configured to change the orientation of the surgical effector about the N degrees of freedom when actuated. In some embodiments, the N+1 input controllers and plurality of cables are further coupled to a pantograph, the pantograph configured to move in a reciprocal manner to the surgical effector when the input controllers and cables are actuated.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Application No.PCT/US2016/049775, filed on Aug. 31, 2016, and entitled “LengthConservative Surgical Instrument,” the contents of which areincorporated herein by reference in their entirety for all purposes.

BACKGROUND Field of Art

This description generally relates to surgical robotics, andparticularly to a surgical wrist with active tensioning.

Description of the Related Art

Robotic technologies have a range of applications. In particular,robotic arms help complete tasks that a human would normally perform.For example, factories use robotic arms to manufacture automobiles andconsumer electronics products. Additionally, scientific facilities userobotic arms to automate laboratory procedures such as transportingmicroplates. Recently, physicians have started using robotic arms tohelp perform surgical procedures. For instance, physicians use roboticarms to control surgical instruments such as laparoscopes.

Laparoscopes with movable tips help perform surgical procedures in aminimally invasive manner. A movable tip can be directed through theabdominal wall to a more remote location of a patient, such as theintestines or stomach. The movable tips in a robotically controlledlaparoscope have several degrees of freedom that mimic a surgeon's wristin traditional surgical operations. These movable tips, also referred asa robotic wrist or simply as a wrist, have evolved with technology andencompass a variety of technologies for creating motion about as manydegrees of freedom as possible while using a minimal number of motorsthe surgical instrument.

Many such robotic wrists use a pre-tensioned loop of cable. This allowsfor the instrument to be driven with a minimum of motors relative toinstruments that are tensioned with a motor for each cable. Such a“closed loop” cabling system makes it more difficult to map motor torqueto cable tension. This is partly because of the preload in the systemand partly due to the frictions the preload causes. End of life for apre-tensioned instrument is usually because the cables loose tensionover time due to a combination of mechanical wear, effects of cleaningchemicals, and stretch of the cables.

SUMMARY

This description relates to a robotic surgical wrist with three degreesof freedom (DOF) that maintains the length and tension of the cablesthat control those DOF throughout the surgical operation.

The surgical robotic system controlling the wrist uses a master/slavesystem in which a master device controls motion of a slave device at aremote location. Generally, the slave device is a robotic surgicalinstrument that approximates a classical surgical tool for a surgicaloperation, e.g. a forceps in a laparoscopy.

In one embodiment, the slave surgical instrument has a surgical effectorfor performing surgical operations at a surgical site with three degreesof freedom in motion, a pitch angle, a first yaw angle, and a second yawangle. Additionally, the surgical effector has a ‘fourth degree offreedom’ which is a measure of the relative yaw angles and the tensionof their respective cables in the surgical effector. The surgicaleffector also a translation degree of freedom along an operation axiscontrolled by an external arm and a rotation degree of freedom about theoperation axis controlled by an external instrument device manipulator.

To control the degrees of freedom of the surgical effector the surgicalinstrument has a set of four input controllers, four cables, areciprocal pantograph, a cable shaft, and a surgical effector. Two ofthe cables couple two pairs of input controllers via the surgicaleffector such that their actuation, e.g. spooling or unspooling,manipulates the length of the cable's segment to create motion of thesurgical effector about the degrees of freedom. The other two cablescouple the two pairs of input controllers to the reciprocal pantographsuch that the actuation creating motion of the surgical effectorscreates a reciprocal motion in the reciprocal pantograph. The reciprocalpantograph maintains a constant length of cable between each pair ofinput controllers by rotating the reciprocal pantograph.

The surgical wrist may be controlled by a computer program designed tointerpret motions of a user into surgical operations at the surgicalsite. This computer program interprets user motion and creates a set ofinstructions for appropriately manipulating the four cables via spoolingand unspooling the input controllers to translate the user motion tomotion of the surgical effector.

BRIEF DESCRIPTION OF DRAWINGS

The disclosed embodiments have other advantages and features which willbe more readily apparent from the following detailed description of theinvention and the appended claims, when taken in conjunction with theaccompanying drawings, in which:

FIG. 1 illustrates an example representation of a surgical roboticsystem.

FIG. 2 illustrates an example representation of a slave device in amaster/slave surgical robotic system.

FIG. 3 illustrates an example representation of the end of a robotic armcoupling to a surgical instrument in a master/slave surgical system.

FIG. 4 illustrates an example representation of the surgical instrumentin a master/slave surgical system.

FIG. 5 illustrates an isometric view of an example support bracketdemonstrating its constituent components.

FIG. 6A illustrates an example representation of a reciprocal pantographof the surgical instrument.

FIG. 6B illustrates an example representation of a tensile state of thereciprocal pantograph of the surgical instrument in a master/slavesurgical system.

FIG. 6C illustrates an example representation of a different tensilestate of the surgical instrument in a master/slave surgical system.

FIG. 7A illustrates an example representation of the surgical effector.

FIG. 7B illustrates an example representation of the surgical effectorwith the effector housing removed.

FIG. 8 illustrates an example coupling of the input controllers to thesurgical effectors of the surgical instrument in a master/slave surgicalsystem.

FIG. 9A illustrates an example of the surgical effector in a neutralstate.

FIG. 9B illustrates the first and second yaw angles of the surgicaleffector being increased.

FIG. 9C illustrates a different example of the surgical effector in aneutral state.

FIG. 9D illustrates the pitch angle of the surgical effector beingincreased.

FIG. 10A illustrates an example of the surgical instrument with allcable connections.

FIG. 10B illustrates an example of reciprocal motion in the surgicalinstrument when the first yaw angle is increased.

FIG. 10C illustrates an example of reciprocal motion in the surgicalinstrument when the first pitch angle is increased.

FIG. 11 illustrates an example alternative cabling for the wrist.

DETAILED DESCRIPTION I. Surgical Robotic Systems

FIG. 1 illustrates an example representation of a master/slave surgicalrobotic system 100 consisting of a master device 110 and a slave device150. Generally, the master device is a command console for a surgicalrobotic system 100. The master device 110 includes a console base 112,display modules 114, e.g., monitors, and control modules, e.g., akeyboard 116 and joystick 118. In some embodiments, one or more of themaster device 110 functionality may be integrated into the slave device150 of the surgical robotic system 100 or another system communicativelycoupled to the surgical robotic system 100. A user 120, e.g., aphysician, remotely controls the surgical robotic system 100 from anergonomic position using the master device 110.

The slave device 150 has a table base 152 to support a surgical table154 upon which a patient 156 is positioned for a surgical procedure at asurgical site 158. At least one robotic arm 160 mounted to at least onelocatable base 162 for manipulating surgical effectors 164, ispositioned in close proximity to the table base 152 and the surgicaltable 154. Rather than having an independent and movable locatable base162, the robotic arms 160 may be coupled to the table base 152. Thetable base 152 and the surgical table 154 may include motors, actuators,or other mechanical or electrical means for changing the orientation ofthe surgical table. In some embodiments the table base 152 and thesurgical table 154 may be configured to change the orientation of thepatient 156 and the surgical table for different types of surgicalprocedures at different surgical sites.

The slave device 150 may include a central processing unit, a memoryunit, a data bus, and associated data communication ports that areresponsible for interpreting and processing signals such as cameraimagery and tracking sensor data, e.g., from the robotic manipulators.The console base 112 may include a central processing unit, a memoryunit, a data bus, and associated data communication ports that areresponsible for interpreting and processing signals such as cameraimagery and tracking sensor data, e.g., from the slave device. In someembodiments, both the console base 112 and the slave device 150 performsignal processing for load-balancing.

The console base 112 may also process commands and instructions providedby the user 120 through the control modules 116 and 118. In addition tothe keyboard 116 and joystick 118 shown in FIG. 1, the control modulesmay include other devices, for example, computer mice, trackpads,trackballs, control pads, video game controllers, and sensors (e.g.,motion sensors or cameras) that capture hand gestures and fingergestures.

The user 120 can control a surgical effector 164 coupled to the slavedevice 150 using the master device 110 in a velocity mode or positioncontrol mode. In velocity mode, the user 120 directly controls pitch andyaw motion of the surgical instrument based on direct manual controlusing the control modules. For example, movement on the joystick 118 maybe mapped to yaw and pitch movement of the surgical effectors 164. Thejoystick 118 can provide haptic feedback to the user 120. For example,the joystick 118 vibrates to indicate that the surgical effectors 164cannot further translate or rotate in a certain direction. The commandconsole 112 can also provide visual feedback (e.g., pop-up messages)and/or audio feedback (e.g., beeping) to indicate that the surgicaleffectors 164 have reached maximum translation or rotation.

In position control mode, the command console 112 uses athree-dimensional (3D) map of a patient and pre-determined computermodels of the patient to control the slave device 150. The commandconsole 112 provides control signals to robotic arms 160 of the surgicalrobotic system 100 to manipulate the surgical effectors to the surgicalsite 158. Due to the reliance on the 3D map, position control moderequires accurate mapping of the anatomy of the patient.

In some embodiments, users 120 can manually manipulate robotic arms 160of the surgical robotic system 100 without using the master device 110.During setup in a surgical operating room, the users 120 may move therobotic arms 160, surgical effectors 164, and other surgical equipmentto access a patient. The surgical robotic system 100 may rely on forcefeedback and inertia control from the users 120 to determine appropriateconfiguration of the robotic arms 160 and equipment.

The display modules 114 may include electronic monitors, virtual realityviewing devices, e.g., goggles or glasses, and/or other means of displaydevices. In some embodiments, the display modules 114 are integratedwith the control modules, for example, as a tablet device with atouchscreen. Further, the user 120 can both view data and input commandsto the surgical robotic system 100 using the integrated display modules114 and control modules.

The display modules 114 can display 3D images using a stereoscopicdevice, e.g., a visor or goggle. The 3D images provide a “surgicalview,” which is a computer 3D model illustrating the anatomy of apatient at the surgical site 158. The “surgical view” provides a virtualenvironment of the patient's interior and an expected location of thesurgical effectors 164 inside the patient. A user 120 compares the“surgical view” model to actual images captured by a camera to helpmentally orient and confirm that the surgical effectors 164 are in thecorrect—or approximately correct—location within the patient. The“surgical view” provides information about anatomical structures, e.g.,the shape of an intestine or colon of the patient, around the surgicalsite. The display modules 114 can simultaneously display the 3D modeland computerized tomography (CT) scans of the anatomy at the surgicalsite. Further, the display modules 114 may overlay pre-determinedoptimal navigation paths of the surgical effectors 164 on the 3D modeland CT scans.

In some embodiments, a model of the surgical effectors is displayed withthe 3D models to help indicate a status of a surgical procedure. Forexample, scans identify a region in the anatomy where a suture may benecessary. During operation, the display modules 114 may show areference image captured by the surgical effectors 164 corresponding tothe current location of the surgical effectors at the surgical site 158.The display modules 202 may automatically display different views of themodel of the endoscope depending on user settings and a particularsurgical procedure. For example, the display modules 202 show anoverhead fluoroscopic view of the surgical end effector during anavigation step as the surgical end effector approaches an operativeregion of a patient.

II. Slave Robotic Device

FIG. 2 illustrates a slave robotic device 200 from a surgical roboticsystem 100 according to one embodiment. The slave device 200 includes aslave base 202 coupled to one or more robotic arms, e.g., robotic arm204. The slave base 202 is communicatively coupled to the master device110. The slave base 202 can be positioned such that the robotic arm 204has access to perform a surgical procedure on a patient, while a usersuch as a physician may control the surgical robotic system 100 from themaster device. In some embodiments, the slave base 202 may be coupled toa surgical operating table for supporting the patient. Though not shownin FIG. 1 for purposes of clarity, the slave base 202 may includesubsystems such as control electronics, pneumatics, power sources,optical sources, and the like. The robotic arm 204 includes multiple armsegments 206 coupled at joints 208, which provides the robotic arm 202multiple degrees of freedom. The slave base 202 may contain a source ofpower 210, pneumatic pressure 212, and control and sensor electronics214—including components such as a central processing unit, data bus,control circuitry, and memory—and related actuators such as motors tomove the robotic arm 204. The electronics 214 in the slave base 202 mayalso process and transmit control signals communicated from the commandconsole.

In some embodiments, the slave base 202 includes wheels 216 to transportthe slave robotic device 150. Mobility of the slave robotic device 150helps accommodate space constraints in a surgical operating room as wellas facilitate appropriate positioning and movement of surgicalequipment. Further, the mobility allows the robotic arms 204 to beconfigured such that the robotic arms 204 do not interfere with thepatient, physician, anesthesiologist, or any other equipment. Duringprocedures, a user may control the robotic arms 204 using controldevices such as the master device.

In some embodiments, the robotic arm 204 includes set up joints that usea combination of brakes and counter-balances to maintain a position ofthe robotic arm 204. The counter-balances may include gas springs orcoil springs. The brakes, e.g., fail safe brakes, may be includemechanical and/or electrical components. Further, the robotic arms 204may be gravity-assisted passive support type robotic arms.

The robotic arm may be coupled to a surgical instrument, e.g. alaparoscope 220, with the robotic arm positioning the surgicalinstrument at a surgical site. The robotic arm may be coupled to thesurgical instrument with a specifically designed connective apparatus230 that allows communication between the surgical instrument and thebase, the base configured to control of the surgical instrument via therobotic arm.

III. Instrument Device Manipulator

FIG. 3 illustrates an embodiment of the end of a robotic arm 300 in amaster/slave surgical system. At the end of each robotic arm, amechanism changer interface (MCI) 310 may couple an instrument devicemanipulator (IDM) 320 to the robotic arm. The MCI 310 can be a set screwor base plate connector. The MCI 310 includes connectors to transferpneumatic pressure, electrical power, electrical signals, and opticalsignals from the robotic arm to the IDM 320.

The MCI 310 removably or fixedly mounts the IDM 320 to a surgicalrobotic arm of a surgical robotic system. The IDM is configured toattach the connective apparatus 230 (e.g., via a support bracket andmounting bracket as described in FIG. 4 below) of a surgical tool to arobotic surgical arm in a manner that allows the surgical tool to becontinuously rotated or “rolled” about an axis of the surgical tool. TheIDM 320 may be used with a variety of surgical tools (not shown in FIG.3), which may include a housing and an elongated body, and which may befor a laparoscope, an endoscope, or other types of end-effectors ofsurgical instruments.

IV. Surgical Instrument

FIG. 4 illustrates an example representation of the surgical instrumentin a master/slave surgical system 400. The surgical instrument iscoupled to the IDM 320 via a support bracket 410 and mounting bracket450. The support bracket 410 and mounting bracket 450 are disk shaped,with a cable shaft 420 centrally located on the disk of the supportbracket and extending outward normal to the plane of the support bracket410 opposite the mounting bracket 450 along an operation axis 430. Thecable shaft 420 couples the surgical effector 440 to the support bracket410 allowing control of the surgical effector by the slave base via therobotic arm and the IDM.

V. Support Bracket

FIG. 5 illustrates an isometric view of an embodiment of the supportbracket, with the mounting bracket not shown, demonstrating itsconstituent components. The support bracket 410 includes a support base510 which is approximately disk shaped with at least one connectivethrough-hole 512 coupled to the outer edge of the disk to assistcoupling the support bracket to the mounting bracket. In someembodiments, there is no connective through-hole for coupling thesupport bracket to the mounting bracket. In other embodiments, there isno mounting bracket and the support bracket directly couples to the IDM.One face of the support base, hereafter the coupling face 514, acts as asupport structure for the input controllers 520, the guidance pulleys530, and the reciprocal pantograph 540. The opposite face of the supportbase 510, hereafter the operation face 516 (not visibly shown), acts asa support structure for the cable shaft 420.

In the center of the support base is an operative through-hole 518through the support base 510 from the coupling face 514 to the operationface 516 along the operation axis 430 for coupling the input controllers520 to the surgical effectors 440 via the cable shaft 420. The operativethrough-hole 518 has a diameter large enough to allow at least fourcable 560 segments to pass unimpeded through the support base 510 fromthe coupling face 514 to the operation face 516.

Along the outer edge of the operative through-hole are a set of fourguidance pulleys 530, two outer 530 a, 530 d and two inner 530 b, 530 cthat are at least partially recessed below the plane of the couplingface. The plane of each guidance pulley 530 is orthogonal to the planeof the coupling face 514, with the plane of a pulley is the plane ofpulley's disc. The pulleys are positioned such that the plane of eachguidance pulley is normal to the edge of the operative through-hole 518with at least a portion of the guidance pulley extended into theoperative through-hole. The guidance pulleys 530 are coupled to thesupport base 510 and configured to rotate about a central guidance axiscoplanar to the plane of the support base 510. In one embodiment, theguidance pulleys 530 are connected to the support base 510 via bearings.The guidance pulleys allow cables 560 to move through the operativethrough-hole 518 without tangling with one another or chaffing againstthe edge of the operative through-hole.

The rays from the operation axis 430 outwards along the plane of theguidance pulleys create a set of four cable axes 550, two outer axes 550a, 550 d and two inner axes 550 b, 532 c. The guidance pulleys 530 arepositioned such that the outer cable axes 550 a, 550 d form a line alongthe support bracket diameter, the angle between an outer cable axis(e.g. 550 a) and the nearest inner cable axis (e.g. 550 b) is a non-zeroangle between 0 and 90 degrees, an example of which is illustrated inFIG. 5 as being approximately 60 degrees. Similarly, the angle betweentwo inner cable axes (e.g. 550 b and 550 c) is an angle between 0 and 90degrees, an example of which is illustrated as approximately 60 degrees.

VI. Cable Shaft

The cable shaft 420 couples the surgical effector 440 to the supportbracket 410 allowing control of the surgical effector by the slave basevia the robotic arm and the IDM. In one embodiment, the cable shaft is along hollow cylinder with an action end and a driver end, the action endcoupling to the surgical effector 440 and the driver end coupling to theoperation face 516 of the support bracket 510. The cable shaft iscoupled to the support bracket 510 such that the cable shaft 420 extendsorthogonally from the support bracket along the operation axis 430. Thecable shaft 420 houses the cables 560 which couple the input controllers520 to the surgical effector 440.

VII. Input Controllers

Two outer input controllers 520 a, 520 d and two inner input controllers520 b, 520 c are coupled to the support base and extend orthogonallyoutwards from the coupling face 514. The input controllers 520 arepositioned along a concentric half ring about the operation axis 430with each input controller radially equidistant from the operation axisalong one of the cable axes 550. The input controllers 520 may be asimilarly shaped to an inverted tiered cylindrical pyramid, withcylinders of increasing radii coupled atop one another. The coupledcylinders of the input controllers 520 are centrally aligned along aspooling axis 556 associated with that particular input controller thatis orthogonal to the coupling face 514 and parallel to the operationaxis 430. The input controllers are positioned such that the twospooling axes 556 of the outer input controllers 520 a, 520 d form aform a line along the diameter of the support bracket similarly to thetwo outer cable axes, and forming similar angles with their closestrespective inner input controllers with respect to the operation axis430 accordingly. The two inner input controllers similarly are locatedat an angle with respect to each other similarly to the two inner cableaxes, as described above.

The support base 510 contains four circularly shaped rotary joints 570.The rotary joints 570 are configured to allow each input controller torotate about its spooling axis, such as 556. The rotary joints 570 areformed such that the top of each rotary joint is substantially flush toor slightly recessed from the coupling face 514 of the support base 510.The rotary joints 570 are similarly positioned to the input controllers520 with each input controller coupled to the center of a rotary jointsuch that the rotation axis of the rotary joint is coaxial with thespooling axis 556 of the associated input controller. In one embodiment,the rotary joint is a bearing.

While not pictured in FIG. 5, the support bracket is further coupled tothe mounting bracket 450 via the input controllers. The mounting bracketcouples to the input controllers such that the top of the inputcontrollers pass through the mounting bracket and the top of the inputcontrollers are substantially flush with the top of the mountingbracket. The mounting bracket is further configured with a similar setof rotary joints coaxial to the rotary joints of the support bracketwhich allows the input controllers to rotate. The input controllers 520and mounting bracket 450 are configured to be coupled to the IDM andactuate the cables 560 to control motion of the surgical effector 440,described in detail in later sections. The cables 560 are coupled to theinput controllers 520 such that the cables are at least partiallywrapped around the input controllers and may spool or unspool aroundcontrollers as they rotate about the spooling axis. Each inputcontroller is coupled to a single cable.

VIII. Reciprocal Pantograph

The reciprocal pantograph 540 is a physical structure containingmultiple physical components that is named as such because it isconfigured to move in a reciprocal manner to the surgical effector,discussed in sections X and XI. Thus, the reciprocal pantograph allowsthe surgical instrument as a whole, the wrist specifically, and thecables within more specifically, to be length conservative. The cablesare tightened using traditional techniques such as a fixed clamp orspooling around a cylinder, which is subject to becoming loose (lesstensioned) over time through normal wear and tear. While cable wear maycause a change in the overall length of the cable, this change iscompensated for by the IDM, robotic arm, and controlling computer tomaintain a length conservative system. The reciprocal pantograph isfurther configured to maintain the length of the cables in the surgicalinstrument when not being controlled by the input controllers and IDM,for example when the surgical instrument is detached from the slavesurgical device.

The reciprocal pantograph has two modes of operation: attached mode, inwhich the surgical instrument is attached to the IDM and robotic armsuch that the IDM and robotic arm are able to actuate the inputcontrollers and control the motion of the surgical effectors; anddetached mode, in which the surgical instrument is detached from the IDMand robotic arm such that the reciprocal pantograph and inputcontrollers passively maintain the length of the surgical cables of thesurgical effector, thereby preventing it from coming loose/falling off.

VIII-A. Reciprocal Pantograph Construction

The reciprocal pantograph 540 is coupled to the support base 510 on thehalf of the coupling face 514 opposite the inner input controllers 524.The reciprocal pantograph 540, shown with an expanded view in FIG. 6,includes two coupled differentials, a rotation shaft, and an armature.The rotation shaft extends orthogonally outward from the coupling face514 with the central axis of the rotation shaft, hereafter reciprocalaxis 558, being parallel to the operation axis 430. The rotation shaftis positioned a radial distance away from the operation axis 430.Additionally, the angle between an outer spooling axis 556, theoperation axis 430, and the reciprocal axis 558 is approximately 90degrees, though in other embodiments it may be at a different angle.

FIG. 6A is an isometric view of the example reciprocal pantograph 540.The reciprocal pantograph consists of an armature 620 coupling twodifferentials 610 a and 610 b. The first differential 610 a couples of apair of pulleys, the first pulley being a reciprocal wrist pulley 612 awith two grooves and the second pulley being a reciprocal member pulley614 a with one groove. The second differential 610 b is similarlyconstructed with a wrist pulley 612 b and a member pulley 614 b. Inanother embodiment, the reciprocal wrist pulleys 612 a and 612 b maycomprise two separate coaxial single groove pulleys or a single pulleywith a single groove large enough to allow for two cables. The armature620 couples the differentials 610 a and 610 b to each other such thatthe reciprocal wrist pulleys 612 a and 612 b are coaxial to each otherand to the reciprocal axis 558. Additionally, the armature 620 couplesthe reciprocal member pulleys 614 a and 614 b of each differential anequal distance from the reciprocal wrist pulleys 612 a and 612 b. Thearmature 620 further couples the reciprocal member pulleys 614 a and 614b such that they are located a non-zero angle apart from each otherabout the reciprocal axis 558. In other embodiments, the reciprocalmember pulleys 612 are a dissimilar distance away from the reciprocalwrist pulleys 614. The reciprocal member pulleys 614 are rotated about atensile axis 630, the tensile axis forming an acute angle to thereciprocal axis 558.

VIII-B. Reciprocal Pantograph Cabling

Within each differential 610, the reciprocal wrist pulley 612 andreciprocal member pulley 614 are further coupled by a cable 560. Forsake of discussion the cable may be described as having an inboundsegment 616 a and an outbound segment 616 b, with the inbound segmentextending from the reciprocal axis 558 towards the tensile axis 630 andthe outbound segment extending from the tensile axis toward thereciprocal axis. As the cables move during use, the segment definitionsare arbitrary, and are defined here for sake of clarity relative to thepulleys, rather than being at fixed locations on the cables themselves.

On the inbound segment 616 a, the cable at least partially loops aroundthe reciprocal wrist pulley 612 in its first groove. The cable then atleast partially loops around the reciprocal member pulley 614, couplingthe reciprocal member pulley to the reciprocal wrist pulley 612transitioning to the outbound segment. On the outbound segment 616 b,the cable then further at least partially loops around the reciprocalmember pulley 614, thereby reverses the direction of the cable afterwhich it is directed away from the tensile axis 630. The outboundsegment of the cable at least partially loops around the second grooveof the reciprocal member wrist pulley 612, after which it is directedaway from the reciprocal axis 558.

VIII-C. Reciprocal Pantograph Motion

FIG. 6B illustrates an example of how the input controllers are coupledto the restraint pantograph. The top tier of each input controller 520,i.e. the cylinder furthest removed from the coupling face of the supportbracket, is configured to removably attach the input controller to acorresponding actuator of the IDM such that the IDM can manipulate therotation of the input controller about their independent spooling axes556 a 556 b 556 c, 556 d. Additionally, each pair of input controllers520 is coupled to one of the differentials 610 of the reciprocalpantograph 540 by a cable 560 such that the inbound segment and outboundsegment of the cable couples the first input controller to the secondinput controller of an input controller pair. In the illustratedembodiment, an outer 520 a and an inner 520 b input controller arepaired by a first cable and the inner 520 c and outer 520 d are pairedby a second cable, but one knowledgeable in the art will recognize thatany two input controllers may be paired together.

While the laparoscopic tool is attached to the IDM to perform operationsat the surgical site, the reciprocal pantograph is in attached mode.While in attached mode, the differentials of the reciprocal pantographmaintain a constant length in each of the cables coupling each pair ofinput controllers. The total length in a cable is manipulated by theinterplay of spooling and unspooling the pair of input controllersassociated with a given cable, as well as by the rotation of therestraint pantograph about the reciprocal axis. To maintain the lengthof the cables, the pulleys in the differentials and the armature rotateabout the reciprocal and tensile axes to create an equal and oppositelengthening (or shortening) to compensate for the shortening (orlengthening) created by spooling or unspooling input controllers abouttheir spooling axes.

FIGS. 6B and 6C illustrate this process and the following paragraphsfurther detail the interaction between the inbound and outbound cablesegments, the reciprocal pantograph, and the input controller pairs. Forclarity, hereafter, the inbound segment of the first cable within thefirst differential is the first segment 660 a, the outbound segment ofthe first cable within the first differential is the second segment 660b, the inbound segment of the second cable within the seconddifferential is the third segment 660 c, and the outbound segment of thesecond cable within the second differential is the fourth segment 660 d.

Additionally, the first input controller of the first controller paircontrols the length of the first segment 660 a; the second inputcontroller of the first controller pair controls the length of thesecond segment 660 b; the first input controller of the secondcontroller pair controls the length of the third segment 660 c; and, thesecond input controller of the second controller pair controls thelength of the fourth segment 660 d. Any pair of cable segmentsintroduced above could be described as an inbound/outbound segment pairdepending on the spooling/unspooling being performed on one the inputcontrollers of the pair at that moment in time. In the illustratedembodiment, an inner and an outer input controller (e.g. 520 a and 520b) are paired, but one knowledgeable in the art will appreciate that theinput controllers may be configured in different pairings.

In the illustrated embodiment, there are five possible states inattached mode for a given cable of an input controller pair coupled by adifferential. In a first state the input controller pair concurrentlydecreases length of the first segment and increases length of the secondsegment. In a second state the input controller pair concurrentlyincreases length of the second segment and decreases length of the firstsegment. In a third state the input controller pair concurrentlyunspools of the first and second segments, resulting in a compensatoryrotation of the reciprocal pantograph about the reciprocal axis toconserve cable length. In a fourth state the input controller pairconcurrently spools the first and second segment, resulting in acompensatory rotation of the reciprocal pantograph about the reciprocalaxis to conserve cable length. In a fifth “neutral” state the inputcontroller pair does not manipulate the cable segments. In all possiblestates, the length of the cable from the first input controller to thesecond controller of an input controller pair is conserved.

FIG. 6B is a planar view of the support bracket which illustrates theinput controllers and the reciprocal pantograph in the first state forthe cable associated with the first 660 a and second 660 b segments. Thefirst input controller 520 a unspools the cable, increasing length 670 a(illustrated as an arrow) in the first segment 660 a while the secondinput controller 520 b spools the same cable decreasing length 670 b ofthe second segment 660 b. This yields rotation of the reciprocal memberpulley 614 about the tensile axis 630, no rotation of the reciprocalwrist pulley 612 about the reciprocal axis 554, no rotation of thearmature 620 about the reciprocal axis 614, and a reciprocal movement ofthe cables in the operative through-hole 518. In this embodiment of thefirst state, the contact area 640 a of the cable in contact with thereciprocal wrist pulley is unchanged. The second state is similar to thefirst with the first and the second input controllers being reversed.

FIG. 6C is a planar view of the support bracket which illustrates theinput controllers and the reciprocal pantograph in the third tensilestate. The first input controller of an input controller pair, e.g. anouter input controller 520 a, pair spools around its spooling axis 556 a(attempting to decrease the length 680 a in the first segment 660 a)while the second input controller, e.g. an inner input controller 520 b,of the input controller pair spools around its spooling axis 556 b(attempting to decrease the length 680 a of the third segment 660 b).This yields rotation of the reciprocal member pulley 614 about thetensile axis 630, rotation of the reciprocal wrist pulley about thereciprocal axis 558, and rotation of the differential about thereciprocal axis 558. In this embodiment of the third state, thedifferential rotates 690 about the reciprocal axis 558 by an amount thatcompensates for the spooling of the cable segments about the inputcontroller pairs such that the contact area 640 b of the cable with thereciprocal wrist pulley reduces and the total length of the cables inthe pantograph is maintained. The fourth state is similar to the thirdstate with the first and the second input controllers simultaneouslyunspooling the first and second segment with the unspooling offset by arotation of the differential about the reciprocal axis.

IX. Surgical Effectors

FIG. 7A illustrates and embodiment of the surgical effector forlaparoscopy in a master/slave surgical system. The surgical effectorconsists of two working members 710, a surgical wrist 720, and aneffector housing 730. FIG. 7B is an illustration of the surgicaleffector with the effector housing removed.

IX-A. Surgical Effectors Construction

The two working members 710 may be designed as robotic version of anexisting surgical tool for performing surgical operations, for examplethe small robotic forceps illustrated FIGS. 7A and 7B. Each workingmember consists of a member pulley 712 with a single groove and forcepshalf 714. The member pulleys have an outer face and an inner face andare able to rotate around a centrally located rotation axis, hereafterthe member axis 740, which is orthogonal to the inner and outer faces.The member pulleys may have centrally located member bore 716 coaxial tothe member axis passing from the inner face to the outer face andorthogonal to the operation axis 430.

Each forceps half 714 has a substantially flat side and a rounded side,the flat side for interacting with tissues in a surgical operation. Thesubstantially flat side may be textured to allow for easier interactionwith tissues in a surgical operation. In another embodiment, the forcepsare configured to interact with needles in a surgical procedure. Eachforceps half 714 is independently coupled to a member pulley 712 suchthat the forceps half is normal to the edge of the member pulley andextends radially away from the member axis 740 in the plane of themember pulley 712. The member pulley 712 is further coupled to theforceps half 714 such that the forceps half also rotates around themember axis 740.

The working members 710 are coupled such that the inner faces of themember pulleys are substantially flush with the member bores 716 andmember axes 740 being coaxial. The working members 710 are furthercoupled such that the flat side of each forceps half are facing oneanother and may be coplanar.

The surgical wrist is a set of two wrist pulleys with four grooves. Thefirst wrist pulley 722 may have a larger radius than the second wristpulley 724. The wrist pulleys have a front face and a back face and areable to rotate around a centrally located rotation axis that isorthogonal to the front and back faces, hereafter the wrist axes 742.Herein, the four grooves of the wrist pulley will be sequentiallyreferenced as one through four from the back side to the front side. Thewrist pulleys 720 may have a centrally located wrist bore 726 coaxial tothe wrist axes 742 passing from the front face to the back face of thewrist pulleys. The wrist axes 742 of each wrist pulley are parallel toone another, orthogonal to the member axes 740, and orthogonal to theoperation axis 420 such that the three types of axes are an orthogonalset 744. The wrist pulleys are positioned such that the front faces arecoplanar, with the first wrist pulley 722 being nearer the action end ofthe cable shaft 420 along the operation axis 430 than the second wristpulley 724.

The effector housing 730 may be a cylindrical protective metal sheathwhich couples the wrist pulleys 720 to the member pulleys 712 whileallowing movement of cables 560 through the sheath. In some embodiments,the effector housing may include a proximal clevis 730 b and a distalclevis 730 c, the proximal clevis coupled to the distal clevis by aconnective pin. The first 720 and second 722 wrist pulleys are coupledto the effector housing 730 by independent set screws 732 that pass fromone side of the housing to the other side of the housing along the wristaxes 742 through the wrist bores 726 in the wrist pulleys 720. Themember pulleys 712 are coupled to the effector housing by a singular setscrew 734 that passes from one side of the housing to the other side ofthe housing along the coaxial member axes 740 through the central memberbores 716 in the member pulleys 712. The member pulleys 712 are furthercoupled to the effector housing with the forceps halves 714 extendingaway from the effector housing towards the active end of the cable shaft420 along the operation axis 430. The housing couples the wrist pulleys720 and the member pulleys 712 such that the member pulleys are nearerthe active end of the cable shaft 720 along the operation axis 430 thanthe wrist pulleys. The effector housing 730 couples the wrist pulleys720 and member pulleys 714 to maintain the orthogonal set of theoperation axis 430, the member axes 740, and the parallel wrist axes742, i.e. the outer face of the member pulley 712, the front faces ofthe wrist pulleys 720, and the operation axis 430 are orthogonal 744.

IX-B. Surgical Effectors Cabling

Within the housing the wrist pulleys 720 and the member pulleys 714 arefurther coupled by two cables. In some embodiments, the cables withinthe effector housing are distinct from the two cables coupling the inputcontrollers to the reciprocal pantograph, hereafter referred to as thethird and the fourth cable for clarity. For sake of discussion thecables may be described as having inbound and outbound segments, withthe inbound segments extending from driver end to the action end withinthe cable shaft and the outbound segments extending from the action endto the driver end within the cable shaft.

Hereafter, the inbound segment of the third cable is the fifth segment750 a and the outbound segment of the third cable is the sixth segment750 b. According to one possible cabling scheme, the inbound segment 650a, the cable at least partially loops around the second wrist pulley inits first groove. The fifth segment 650 a then at least partially loopsaround the first grooves of within the housing the first wrist pulley722, coupling the first wrist pulley to the second wrist pulley. Theinbound segment then at least partially loops around the first groove ofthe first member pulley 712, coupling the first wrist pulley to themember pulley. The inbound segment 750 a at least partially loopingaround the first member pulleys 712 reverses the direction of the cableaway from the action end and begins the outbound segment 650 b. On theoutbound segment 650 b, the cable at least partially loops around thethird groove of the first wrist pulley 722. The outbound segment 650 bthen at least partially loops around the third groove of the secondwrist pulley 724.

Similarly, the inbound segment of the fourth cable is the seventhsegment 750 c and the outbound segment of the fourth cable is the eighthsegment 750 d. Continuing the same cabling scheme above, the inboundsegment 750 c at least partially loops around the second grooves of thewrist pulleys 720 on the inbound route, at least partially loops aroundthe second member pulley 712 reversing the direction to begin theoutbound segment 750 d, and at least partially loops around the fourthgrooves of the wrist pulleys

In the illustrated embodiment, the inbound cables at least partiallyloop one half of the second wrist pulley and the opposite half of thefirst wrist pulley. It will be obvious to one skilled in the art thatthese halves may be reversed.

In the illustrated embodiment, the third cable at least partially loopsaround the wrist pulleys in the first groove on the inbound route andthe third groove on the outbound route while the fourth cable at leastpartially loops around the wrist pulleys in the second groove on theinbound route and the fourth groove on the outbound route. It will beobvious to one skilled in the art that the grooves of the inbound andoutbound routes for the third and fourth cables may be configured in adifferent manner.

FIG. 8 illustrates how the input controllers 520 are coupled to thesurgical effector 440. The bottom tier of each input controller 520 iscoupled to a rotary joint 570 on the support bracket 410. Each innerinput controller and outer input controller pair (e.g. 520 a and 520 b)is coupled to the surgical effector 440 by a cable that passes throughthe operative through-hole 518 such that the inbound segment fifthsegment 750 a of the outer input controller is coupled to the outboundsixth segment 750 b of the inner input controller via the surgicaleffector 440. In alternative configurations, the inbound and outboundsegments as well as the paired input controllers are interchangeable.

IX-C Surgical Effector Degrees of Freedom

In the described configuration, the surgical effector has threecontrollable degrees of freedom: a first yaw angle 910, a second yawangle 920, and a pitch angle 930 illustrated in FIGS. 9A-9D.

As illustrated in FIGS. 9A and 9B, the first degree of freedom is motionof the first forceps half 714 as the first member pulley 712 rotates 912about the member axis 740, i.e. the yaw axis, moving the forceps half714 in the plane of the first member pulley such that the forceps halfcreates a first yaw angle 910 with the operation axis 430.

Similarly, the second degree of freedom is motion of the second forcepshalf 714 as the second member pulley 712 rotates about the member axis710, i.e. the yaw axis, moving the second forceps half in the plane ofthe second member pulley such that the forceps half creates a second yawangle 920 with the operation axis 430.

As illustrated in FIGS. 9C and 9D. the third degree of freedom is motionof the working members as the first wrist pulley rotates 922 about thefirst wrist axis 742, i.e. the pitch axis, moving the working members inthe plane of the first wrist pulley 722 such that the working memberscreate first yaw angle 920 with the operation axis 430.

In the described embodiment, the first and the second yaw angles arecoplanar and the plane of the pitch angle is orthogonal to the plane ofthe yaw angles. In other embodiments, the first yaw angle, the secondyaw angle, and the pitch angle may have different orientations to theoperation axis. In still other embodiments, the first and second yawangles may not be coplanar.

The surgical effector may also move in two additional degrees offreedom: a rotation angle and a translation distance. The rotation angleis created by rotation of the IDM and MCI about the operation axis. Thetranslation distance is created by motion of the robotic arms such thatthe cable shaft translates along the operation axis.

IX. Surgical Effector Movement

Movement about the three degrees of freedom in this system is created byrotation of the member pulleys 714 and the wrist pulleys 720 about theirrespective axes. The rotation of the pulleys about their axes is causedby the input controllers spooling or unspooling the cables to controlthe length of the cables.

FIGS. 9A-9D further demonstrate a method for causing motion of thesurgical effector about the three controllable degrees of freedom bycontrolling length in the cables. In this embodiment, each inputcontroller is coupled to either the input or output segment of the thirdcable or the input or output segment of the fourth cable in the surgicaleffector. The first input controller of the first controller paircontrols the length of the fifth segment 750 a; the second inputcontroller of the first controller pair controls the length of the sixthsegment 750 b; the first input controller of the second controller paircontrols the length of the seventh segment 750 c; and, the second inputcontroller of the second controller pair controls the length of theeighth segment 750 d.

FIG. 9A illustrates the surgical effector in an example “neutral” state,i.e. the first yaw angle 910, the second yaw angle 920, and the pitchangle 930 have no offset from the operation axis 430 with no cablesegment length being modified. The first yaw angle 910 is manipulated bycontrolling length in the fourth cable such that the length of theseventh segment increases 920 while the length of the eighth segmentdecreases 922. This configuration causes the fourth cable to move whichin turn causes first member pulley to rotate about the yaw axis 740 suchthat the first yaw angle 910 between the half forceps 714 and theoperation axis 430 increases. In a reciprocal configuration, the firstyaw angle 910 can be decreased by decreasing the length of the seventhsegment and increasing the length of the eighth segment. In bothconfigurations, the total length of the surgical cable is maintained.

Similarly, the second yaw angle is manipulated by controlling length inthe third cable such that the length of the fifth segment 750 aincreases while the length of the sixth segment 750 b decreases. Thisconfiguration causes the fourth cable to move which in turn causessecond member pulley to rotate about the yaw axis 740 such that thesecond yaw angle 920 between the half forceps and the operation axis 430increases. In a reciprocal configuration, the third cable moves suchthat the yaw angle can be decreased by increasing the length of theeighth segment and decreasing the length of the seventh segment.Additionally, motion of the forceps halves about the yaw axes can be ineither direction away from the operation axis in the plane of memberpulleys. In both configurations, the total length of the surgical cableis maintained.

In some embodiments, the manipulation of segment length of the cablescreates an additional ‘degree of freedom,’ such as grip strength. Inthese embodiments, the motion about the first and second degrees offreedom may limit one another, i.e. one forceps half is unable to changeits yaw angle 910 due to the position and yaw angle 920 of the otherforceps half. This may occur, for example, due to an object being heldbetween the forceps halves. The amount of electrical load measured inthe system when the first and second degrees of freedom limit oneanother provides a measure of grip strength.

FIG. 9C illustrates the surgical effector in a neutral state, i.e. thefirst yaw angle 910, the second yaw angle 920, and the pitch angle 930have no offset from the operation axis 430 with no cable segment beingmanipulated by an input controller. The pitch angle 930 is manipulatedby controlling length in the third and fourth cables. Length in thefifth and sixth segments is increased 924 while length in the seventhand eighth segments is decreased 926 causing the first wrist pulley torotate 914 about the pitch axis. This configuration causes the third andfourth cables to move which increases the pitch angle between theworking members 710 and the operation axis 430 in the plane of the firstwrist pulley 722. Rotation of the effectors about the pitch anglecompensates for the increasing and decreasing of length of the segmentssuch that the first and second cables are length conservative. In areciprocal configuration, the pitch angle can be decreased by decreasinglength in the fifth and sixth segments while increasing length in theseventh and eighth segments. In all configurations, the length of thesurgical cables is conserved. Additionally, motion of the workingmembers about the pitch axis can be in either direction away from theoperation axis in the plane of the wrist pulley.

The above description is a configuration controlling the degrees offreedom in which each movement is asynchronous and controlledindependently, e.g. first opening one forceps half and then pitching thewrist, etc. However, in most robotic surgical operations the degrees offreedom are changed simultaneously, e.g. opening the forceps whileconcurrently rotating their orientation at the surgical site. Oneskilled in the art will note that simultaneous motion about the threecontrollable degrees of freedom is accomplished by a more complexcontrol scheme for spooling and unspooling the input controllers tocontrol the four cables and the segment lengths.

In one embodiment, this control scheme is a computer program running onthe control base of the master device configured to interpret themotions of the user into corresponding actions of the surgical effectorat the surgical site. The computer program may be configured to measurethe electric load required to rotate the input controllers to computethe length and/or movement in the cable segments. The computer programmay be further configured to compensate for changes in cable elasticity,(e.g. if the cables are a polymer), by increasing/decreasing the amountof rotation needed for the input controllers to change the length of acable segment. The tension may be adjusted by increasing or decreasingthe rotation of all the input controllers in coordination. The tensioncan be increased by simultaneously increasing rotation, and the tensioncan be decreased by simultaneously decreasing rotation. The computerprogram may be further configured to maintain a minimum level of tensionin the cables. If the tension in any of the cables is sensed to dropbelow a lower minimum tension threshold, then the computer program mayincrease rotation of all input controllers in coordination until thecable tension in all cables is above the lower minimum tensionthreshold. If the tension in all of the cables is sensed to rise above aupper minimum tension threshold, then the computer program may decreaserotation of all input controllers in coordination until the cabletension in any of the cables is below the upper minimum tensionthreshold. The computer program may be further configured to recognizethe grip strength of the operator based on the load of the motorsactuating the input controllers coupled to the cable segments,particularly in a situation where the working members are holding on toan object or are pressed together. More generally, the computer programmay be further configured to further control the translation androtation of the surgical instrument via the robotic arm and IDM.

X. Reciprocal Motion

The reciprocal pantograph is configured to mimic the motion of thesurgical effector in a reciprocal manner. FIGS. 10A-10C illustrateexamples of the reciprocal motion in the surgical instrument.

FIG. 10A illustrates an example wiring of the slave device laparoscopein the neutral state. The outer input controller 520 a and the innerinput controller 520 b of a first input controller pair are coupled bythe first and the third cables and control the spooling and unspoolingof cable segments. The first cable couples the input controller pairwithin the reciprocal pantograph 540 via the first 660 a and second 660b cable segments. The third cable couples the input controller pairwithin the surgical effector 440 via the fifth 750 a and sixth 750 bsegment. The length in the first and second cable segments is controlledby rotating the outer 520 a and inner 520 b input controllers abouttheir spooling axes 524, respectively. This rotation concurrentlychanges the length in the fifth and sixth cable segments in a reciprocalmanner, respectively, e.g. increasing length in the first segment 750decreases length in the fifth segment 662, conserving the total cablelength between the input controllers.

The inner input controller and the outer input controller of a secondinput controller pair are coupled by the second and the fourth cablesand control the spooling and unspooling of cable segments. The innerinput controller 520 c and the outer input controller 520 d of a firstinput controller pair are coupled by the second and the fourth cablesand control the segment length. The second cable couples the inputcontroller pair within the reciprocal pantograph 540 via the third 660 cand fourth 660 d cable segments. The fourth cable couples the inputcontroller pair within the surgical effector 440 via the seventh 750 cand eighth 750 d segment. The length of the third and fourth cablesegments is controlled by rotating the inner 520 c and outer 520 d inputcontrollers about their spooling axes 524, respectively. This rotationconcurrently changes the length of the seventh and eighth cable segmentsin a reciprocal manner, respectively, e.g. increasing length in thethird segment decreases length in the seventh segment.

FIG. 10B shows first an embodiment in which the first yaw angle 910 ofthe surgical effector 440 is increased. The yaw angle is controlled byspooling and unspooling the first input controller pair, 520 a and 520b, such the length of the fifth segment decreases 1000 while the lengthof the sixth segment increases 1002. As the yaw angle increases, thelength in the first segment increases 1004 while length in the secondsegment decreases 1006 such that, within the restraint pantograph, themember pulley rotates about the tensile axis. In this configuration, theoverall length of the third cable is maintained in the reciprocalpantograph 540, and the length of the first cable is maintained in thesurgical effector and cable shaft. The second yaw angle may bemanipulated by similarly spooling the second pair of input controllersto manipulate the length of the segments of the third and fourth cables.Either yaw angle may be decreased by manipulating segment lengths withthe input controllers in an inverse manner.

FIG. 10C shows an embodiment in which the pitch angle 930 of thesurgical effector 440 is increased. The pitch angle of the surgicaleffector is controlled by unspooling the first cable such that thelength of the fifth segment 1010 and length of sixth segment 1012attempts to increase while simultaneously spooling the second cable suchthat the length of the seventh segment 1020 and length of eighth segment1022 attempts to decrease. The change of the pitch angle in the surgicaleffector compensates for the spooling and unspooling of the cables suchthat the first and second cables are length conservative. As the pitchangle 930 increases, the length of the first segment 1014 and length ofthe second segment 1016 increases while length of the third segment 1024and fourth segment 1026 decreases such that, within the restraintpantograph, the wrist pulleys and armature rotate about the reciprocalaxis 1030. In this configuration the overall length of the third cableis maintained in the reciprocal pantograph as discussed previously. Thepitch angle may be decreased by manipulating segment length of thecables with the input controllers in an inverse manner.

XI. Detached Mode

While performing surgical operations at the surgical site the reciprocalpantograph and input controllers are operating in attached mode and theinput controllers manipulate the degrees of freedom of the surgicaleffector.

The input controllers and reciprocal pantograph may also operate indetached mode in which the input controllers are configured to maintainthe lengths of the cables in the restraint pantograph. This is usefulwhen attaching or detaching the surgical instrument from the IDM androbotic arm. To remove the surgical instrument from the IDM and roboticarm, the cables may be manipulated to achieve a particular length thatwill be maintained through the period between uses of the surgicalinstrument.

In another embodiment, the length of the first through fourth cables arecontrolled during detached mode to achieve a desired result viaactuation of a mechanism other than the input controllers; for example,the mechanism may be a switch, a button, a lever, a pin, or similar. Insome embodiments, actuation of the alternate mechanism may release anyheld object from the effectors; move cable positions towards neutralpositions; or, move the effectors to a neutral position for removal,etc.

XII. Alternate Embodiments

In an alternative embodiment of attached mode operation, similarlyconfigured to FIG. 6, the restraint pantograph may be physically rotatedabout the reciprocal axis such that one degree of freedom of thesurgical effector may be manipulated. The degree of freedom manipulateddepends on how the input controller pairs are coupled.

FIG. 11 shows the surgical effector with the fifth through eighth cablesegments labelled, 750 a-750 d. The input controllers are coupled intotwo pairs by the differential and the surgical effector. With four cablesegments there are three distinct pairing possibilities for the twocables in the surgical effector: (1) the fifth and sixth segmentspairing the first input controller pair and the seventh and eighthsegments pairing the second input controller pair, (2) the fifth andseventh segment pairs the first input controller pair and the sixth andeighth segment pairs the second input controller pair, and (3) the fifthand eighth segment pair the first input controller pair and the sixthand seventh segments part the second input controller pair.

The surgical instrument is configured such that rotation of thereciprocal pantograph spools and unspools the cable segments pairing oneinput controller pair while reciprocally unspooling and spooling theother input controller pair. With this configuration, rotation of thereciprocal pantograph yields three different motions of the surgicaleffector depending on the input controller pairings: the first possiblepairing yields manipulation of the pitch angle, the second possiblepairing yields simultaneous manipulation of both yaw angles in the samedirection, and the third possible pairing yields simultaneousmanipulation of both yaw angles in opposing directions.

These pairing combinations may be incorporated in to the tool for apotential mechanical override of the surgical instrument in specificsituations, e.g. emergency release, power outage etc. For example thethird pairing allows for an emergency command to cause the surgicaleffectors to automatically release an object being held, allowing morerapid removal of the surgical instrument in case of emergency.

XIII. Additional Considerations

Upon reading this disclosure, those of skill in the art will appreciatestill additional alternative structural and functional designs throughthe disclosed principles herein. Thus, while particular embodiments andapplications have been illustrated and described, it is to be understoodthat the disclosed embodiments are not limited to the preciseconstruction and components disclosed herein. Various modifications,changes and variations, which will be apparent to those skilled in theart, may be made in the arrangement, operation and details of the methodand apparatus disclosed herein without departing from the spirit andscope defined in the appended claims.

As used herein any reference to “one embodiment” or “an embodiment”means that a particular element, feature, structure, or characteristicdescribed in connection with the embodiment is included in at least oneembodiment. The appearances of the phrase “in one embodiment” in variousplaces in the specification are not necessarily all referring to thesame embodiment.

Some embodiments may be described using the expression “coupled” and“connected” along with their derivatives. For example, some embodimentsmay be described using the term “coupled” to indicate that two or moreelements are in direct physical or electrical contact. The term“coupled,” however, may also mean that two or more elements are not indirect contact with each other, but yet still co-operate or interactwith each other. The embodiments are not limited in this context unlessotherwise explicitly stated.

As used herein, the terms “comprises,” “comprising,” “includes,”“including,” “has,” “having” or any other variation thereof, areintended to cover a non-exclusive inclusion. For example, a process,method, article, or apparatus that comprises a list of elements is notnecessarily limited to only those elements but may include otherelements not expressly listed or inherent to such process, method,article, or apparatus. Further, unless expressly stated to the contrary,“or” refers to an inclusive or and not to an exclusive or. For example,a condition A or B is satisfied by any one of the following: A is true(or present) and B is false (or not present), A is false (or notpresent) and B is true (or present), and both A and B are true (orpresent).

In addition, use of the “a” or “an” are employed to describe elementsand components of the embodiments herein. This is done merely forconvenience and to give a general sense of the invention. Thisdescription should be read to include one or at least one and thesingular also includes the plural unless it is obvious that it is meantotherwise.

What is claimed is:
 1. A surgical instrument comprising: a surgicaleffector with at least N degrees of freedom, the surgical effector formanipulation of objects at a surgical site; at least N+1 independentlyoperable input controllers configured to control the surgical effector;a pantograph comprising at least one differential; and a plurality ofcables configured such that actuation of the input controllersmanipulates the cables, the cables further configured such that: atleast one cable couples at least one input controller to the surgicaleffector such that manipulation of the at least one cable with the atleast one input controller moves the surgical effector, and at least onecable couples the pantograph to at least one of the input controllerssuch that manipulation of the at least one cable with the at least oneinput controller moves the pantograph.
 2. The surgical instrument ofclaim 1 wherein the at least N degrees of freedom comprise a combinationof at least one of pitch, yaw, and grip.
 3. The surgical instrument ofclaim 1, wherein the input controllers are further configured such thatactuation of the input controllers rotates the input controllers about arotation axis, the rotation of the input controllers spooling orunspooling the cables about the input controllers.
 4. The surgicalinstrument of claim 3, wherein actuation of the input controllers causesmotion of the surgical effectors creates a reciprocal motion in thepantograph.
 5. The surgical instrument of claim 3, wherein thepantograph is further configured such that motion of the cables createsan inverse motion of the pantograph.
 6. The surgical instrument of claim1, wherein actuation of the input controllers does not change the lengthof the cables.
 7. The surgical instrument of claim 1, further comprisinga cable shaft separating the surgical effector from the at least N+1input controllers along an operation axis.
 8. The surgical instrument ofclaim 7, further comprising a support bracket for mounting the inputcontrollers, pantograph, and cable shaft.
 9. The surgical instrument ofclaim 8, further comprising a manipulator wherein the manipulatorcomprises at least N+1 motors for controlling the at least N+1 inputcontrollers.
 10. The surgical instrument of claim 9 wherein thepantograph is configured to maintain the state of the cables when thesupport bracket is not attached to the manipulator.
 11. The surgicalinstrument of claim 9, wherein the support bracket is removablyattachable to the manipulator.
 12. The surgical instrument of claim 1,wherein at least one of the cables couples a pair of the inputcontrollers via the surgical effector such that actuation of the pair ofinput controllers creates motion of the end effector.
 13. The surgicalinstrument of claim 12, wherein at least one of the cables couples thepair of the input controllers via the pantograph such that actuation ofthe pair of the input controllers creates motion of the pantograph,wherein the motion of the pantograph is reciprocal of the motion of theend effector.
 14. The surgical instrument of claim 1, wherein thepantograph comprises N degrees of freedom, each of the N degrees offreedom corresponding to one of the N degrees of freedom of the endeffector, wherein motion of the end effector in any one of the N degreesof freedom of the end effector creates a reciprocal motion in thecorresponding one of the one of the N degrees of freedom of thepantograph.
 15. The surgical instrument of claim 1, wherein the at leastN+1 independently operable input controllers are grouped into pairs inwhich one of the pairs is configured to spool while the other one of thepairs is configured to unspool.
 16. The surgical instrument of claim 15,wherein, for each of the pairs, each of the independently operable inputcontrollers is connected to an opposite end of one of the at least onecables that is coupled to the surgical effector.
 17. A surgical wristthat moves with at least N degrees of freedom, wherein at least one ofN+1 surgical cables are coupled to each of at least N+1 independentlyoperable input controllers, a pantograph, and the surgical wrist, theindependently operable input controllers configured to control motion ofthe wrist when actuated such that an inverse motion of the pantographoccurs to conserve the length of the surgical cables.
 18. The surgicalwrist of claim 17, wherein the at least N degrees of freedom comprise acombination of at least one of pitch, yaw, and grip.
 19. The surgicalwrist of claim 17, wherein actuation of the input controllers rotatesthe input controllers about a rotation axis, the rotation of the inputcontrollers spooling or unspooling the surgical cables about the inputcontrollers.
 20. The surgical wrist of claim 19, wherein spooling orunspooling the surgical cables about the input controller creates motionof the surgical wrist.
 21. The surgical wrist of claim 17, wherein thepantograph further comprises at least one differential, the differentialconfigured to rotate about an operation axis to maintain the length ofsurgical cables.
 22. The surgical wrist of claim 17, further comprisinga support bracket for mounting the input controllers and the surgicalwrist.
 23. The surgical wrist of claim 17, further comprising amanipulator wherein the manipulator comprises at least N+1 motors forcontrolling the at least N+1 input controllers, the manipulatorremovably attachable to the support bracket.
 24. The surgical wrist ofclaim 17, wherein the pantograph is coupled to at least one of thesurgical cables and at least one of the input controllers, thepantograph configured to maintain a constant length of the cables whenthe surgical wrist is not attached to a manipulator.
 25. A surgicalinstrument comprising: a surgical effector with at least N degrees offreedom, the surgical effector for manipulation of objects at a surgicalsite; at least N+1 independently operable input controllers configuredto control the surgical effector; a pantograph comprising at least onedifferential; a plurality of members configured such that actuation ofthe input controllers manipulates the members, the members furtherconfigured such that: at least one member couples at least one inputcontroller to the surgical effector such that manipulation of the atleast one member with the at least one input controller moves thesurgical effector; at least one member couples the pantograph to atleast one of the input controllers such that manipulation of the atleast one member with the at least one input controller moves thepantograph.